PTEN-deficient intestinal stem cells initiate intestinal polyposis

Intestinal polyposis, a precancerous neoplasia, results primarily from an abnormal increase in the number of crypts. Crypts contain intestinal stem cells (ISCs). Thus intestinal polyposis provides an ideal condition for studying stem cell involvement in polyp/tumor formation. Using a conditional knock-out mouse model, we found that the tumor suppressor Phosphatase of Tension homolog (PTEN) governs the proliferation rate and number of ISCs and loss of PTEN results in an excess of ISCs. In PTEN mutants, excess ISCs initiate de-novo crypt formation and crypt fission, recapitulating crypt production in fetal/neonatal intestine. Microarray studies were used to profile the changes in gene expression that occurred when PTEN was knocked out in the intestine.

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He XC, Yin T, Grindley JC, Tian Q, Sato T, Tao WA, Dirisina R, Porter-Westpfahl KS, Hembree M, Johnson T, Wiedemann LM, Barrett TA, Hood L, Wu H, Li L